Weft controller



March 18, 1969 E. LOEPFE 3,433,273

WEFT CONTROLLER Filed Oct. 5. 1967 INVENTOR- ERICH LOEPFE B mww gw ATTORNEYS United States Patent 8 Claims ABSTRACT OF THE DISCLOSURE A weft controller has a base made of rubber or rubberlike material and fixed to the shuttle and a sheet carried by the base and having an edge engaged by the weft moving out of the shuttle. Due to the resiliency of the base, the sheet will be maintained in an inclined position by the weft but will be swung into a position of rest when the yarn is broken. The weft controller is connected with 2. preferably optical signalling device also carried by the shuttle. The base is mounted so as to prevent penetration of dust or dirt to the signalling device.

This invention relates to a weft controller and refers more particularly to a device for controlling weft yarn in loom shuttles wherein the yarn is guided over a swingable mechanical feeler which is held in a predetermined position by the action of a force exerted upon it by the normally running yarn and opposed to a releasing force, and wherein the position of the feeler controls a device connected with the loom.

A weft feeler of this type has the task of determining whether yarn is present in the shuttle at the location being supervised, namely whether, for example, it was properly threaded and whether the yarn is whole, that is, unbroken; in case of a defect, the feeler stops the loom or releases an alarm signal.

Since the control actually takes place in movable shuttles, informtaion about the condition of the yarn must be transmitted either continuously or within predetermined time intervals from the shuttle to the actuating device connected with the loom.

The construction of such a weft controller has already been carried out in different ways without leading to a satisfactory result in actual practice, however. More specifically, weft controllers are known wherein the yarn extending from a weft spool is guided around a swingably mounted member which is actuated when the forces exerted upon it by a movable unbroken yarn are diminished or disappear altogether. Then the member tips under the action of a release spring or a magnetic releasing force into a position deviating from its normal position and therefore, characteristic of the defective condition of the yarn. In order to transmit information concerning the actual position of the feeler to the actuating device, the feeler is connected, for example, with a signalling device which reflects or interrupts a bundle of light rays of an optical feeler device in one of two positions.

Prior art constructions of feelers have serious defects, particularly when used in automatic looms. In the first place, they cannot comply with contradictory requirements of adequate strength with respect to the strain of the moving shuttle and the running yarn and of the sufiiciently high sensibility for thin yarns. This concerns above all the size of the movable parts and of the release spring. Another drawback is the possibility of damage caused by the wear and dirtying at the bearings when edge bearings or pivot bearings are used, and by the accumulation of dust on parts of the signaling device open to the yarn passage.

An object of the present invention is to provide a weft controller of the above-described type which will not have the drawbacks of prior art constructions.

Other objects will become apparent in the course of the following specification.

In the accomplishment of the objectives of the present invention it was found desirable to provide a feeler which is fixed to the shuttle by an elastic rubber base. Such an elastic rubber base can combine the fundamental function of a bearing with the function of release spring and can be precisely adapted to the requirements of yarn feeling. It is insensitive to mechanical strains caused by the manner of movement of the shuttle and, for example, by knots which may appear in the yarn, and is not subjected to any appreciable wear.

Furthermore, this type of connection of the feeler with the shuttle body has the advantage that it makes possible the formation of a smooth yarn channel which is desirable for the movement of the yarn and the flow of air in the yarn channel; an additional important advantage is that this connection prevents the passage of dust from the yarn channel into the space wherein the signalling device is located.

The invention will appear more clearly from the following detailed description when taken in connection with the accompanying drawing, showing by way of example, a preferred embodiment of the inventive idea.

In the drawing:

FIGURE 1 is a perspective view of the end portion of a shuttle, partly in section, showing the feeler provided in the yarn channel of the threading block.

FIGURE 2 is a section through hte threading block and feeler transversely to the direction of the yarn.

FIGURE 3 is a section through the base of the feeler in the direction of the yarn.

The end portion 1 of a shuttle which is shown in FIG. 1 carries a threading block 2 for the guiding of the yarn 3 out of the inner space 4 of the shuttle. In the drawing the front wall of the threading block is shown as being partly broken off and the yarn guiding members and the outlet of the yarn have not been illustrated to provide a clearer view of the feeler 5.

The yarn which is pulled off the weft spool is guided between the jaws of a yarn brake 6 which are resiliently pressed against each other; then the yarn slides over the feeler 5 and moves out of the shuttle through guiding members (not shown). The flap-like feeler 5 is swung by the moving yarn and assumes the position shown in full lines. If the yarn breaks so that its movement ceases, the feeler is raised by the release force exerted by its base into the rest position 5' shown by broken lines. As already stated, the swinging of the feeler out of its rest position is efiected primarily by the movement of the yarn. The friction between the yarn and the feeler participates in this effect but according to a preferred embodiment this friction should be quite small. In that case it is necessary, however, to provide the greatest possible change of the direction of the yarn at its contact area with the feeler. This is attained by suitably guiding the yarn in front of and behind the feeler.

The position of the feeler is indicated by a lug 7 which is connected with the feeler by the U-shaped bridle 14. In the swung position of the feeler the lug 7 covers, for example, a reversing reflector (not shown), so that a feeler ray of light directed from above will not be reflected. On the other hand, in the position 7 of the lug which is shown by broken lines and which corresponds to the position 5 of the feeler, the reflector is uncovered and will provide a signalling impulse if it is optically tested.

In this embodiment the lug and the reflector constitute the above-mentioned signalling device which provides a contact-free control at the location of the feeler by the loom.

As already stated, FIG. 2 shows a section transverse to the direction of the yarn through the threading block and the feeler. The feeler comprises a sheet 8 which is in contact with the yarn 3 and which is made preferably of a ceramic material. The upper edge of the sheet 8 has the shape of a saddle for guiding the yarn. As shown in FIGS. 2 and 3, the sheet 8 is carried by a base 9 consisting of rubber or some other material having the same elastic properties. The base has in cross section substantially in the shape of an inverted T, the sheet 8 being fixed to the upwardly extending leg of the T, while the ends of the transversely extending portion are connected to the threading block. This connection takes place by firmly attaching the opposite edges of the base 9 to adjacent surfaces of the yarn guiding channel 11 so that the space or chamber 10 which contains the signalling device and which extends below the base is separated from the yarn guiding channel 11 in a manner preventing any penetration of dust. The space 10 is also enclosed by the bottom 12 of the threading block and by a window lens 13 so that the device is protected from dirt or any possibility of damage to the movable and optical parts of the signalling device.

As already stated, the bridle connection 14 causes the lug 7 to follow the movements of the sheet 8. It should be noted that the instantaneous axis of rotation of the swinging movement of the feeler is not rigidly fixed in space, which makes the device particularly yieldable and unafiected by yarn pressure. f additional importance for the facility of movement of the feeler is the hollow recess of the base (FIG. 3) in the space wherein the instantaneous axis of rotation is located. This provides for very soft resiliency of the feeler in the direction of movement of the yarn. On the other hand, the feeler has the required stiffness in the transverse direction.

The resiliency of the rubber base can be also adapted to special requirements by suitable shaping and, if advisable, by the use of a resilient wire insert.

To increase the damping of the movable members 8, 9, 14 and 7, the space can be filled with a liquid; however, it is also possible to merely fill the above-mentioned hollow recess of the base with a substance of salvelike or paste-like consistency and having a corresponding viscosity.

The resiliency, the masses and the damping of the movable parts are advantageously so selected that the duration of the movement, namely, the time of the return from the depressed position to the position of rest, amounts to a few milliseconds. Furthermore, if care is taken that the actuation of the signalling device (for example, the covering or uncovering of the reflector) takes place only after the movable system has carried out already a part of its return movement from the depressed position (which can be achieved, for example, by a corresponding arrangement of the reflector and the shape of the covering lug), then a safe provision is made that the feeler will not respond to short disturbances of the yarn movement which can result, for example, from the loosening of a thread loop. It is also advisable to locate the center of gravity of the movable system close to the axis of rotation to eliminate as much as possible the influence of the movement of the shuttle.

The use of the U-shaped bridle 14 for transmitting the movement of the sheet 8 to the lug 7 has the advantage that the signalling lug-reflector system can be placed very closely to the upper surface of the shuttle. This provides the best possible conditions for the operation of the feeler.

The described basic conception of a feeler makes it possible in all cases to provide not only a perfect operation of the releasing force and a particularly simple mechanical structure, but also-as is clear from the described embodimentto construct the yarn channel in a particularly advantageous manner and to arrange the signalling member in a closed space separated from the channel. These advantages contribute to the fact that the weft controller of the present invention constitutes a functionally secure supervisory device 'best suited for continuous operational requirements.

It is also apparent that various modifications may be made in the described and illustrated embodiment without exceeding the scope of the present invention.

What is claimed is:

1. In combination with a loom shuttle having a channel for the weft, a weft detecting mechanism having a weft feeler comprising a member adapted to be engaged by the weft and a base carrying said member and fixed to the shuttle, said base consisting of an elastic resilient material, whereby said member is adapted to be bent by said weft, a signalling device, and means operatively connecting said signalling device with said weft feeler.

2. A weft feeler in accordance with claim 1, wherein said base has substantially the shape of an inverted T in cross section, the upwardly extending leg of the T carrying said member, the transversely extending bottom portion of the T being fixed to said channel.

3. A weft feeler in accordance with claim 2, wherein said base has an inner hollow space open to the bottom of the base.

4. A weft feeler in accordance with claim 1, wherein said member consists of a sheet having an edge adapted to engage the weft, said member being carried by the upper swingable portion of said base.

5. A weft feeler in accordance with claim 1, wherein said shuttle has a chamber containing said signalling device, said base separating said chamber from said channel to prevent penetration of dust into said chamber.

6. A weft feeler in accordance with claim 5, comprising additional means closing said chamber to prevent penetration of dust into said chamber.

7. A weft feeler in accordance with claim 5, wherein said signalling device comprises a reflector and a lug covering said reflector in the bent position of said member.

8. A weft feeler in accordance with claim 7, wherein said reflector is located close to the upper surface of the shuttle.

References Cited UNITED STATES PATENTS 2,079,535 5/1937 Tebo 139220 2,314,485 3/1943 Draper et al 1392.l2 3,298,401 1/ 1967 Stutz 13937l FOREIGN PATENTS 1,343,670 10/1963 France.

357,730 10/1931 Great Britain.

876,679 5/ 1953 Germany.

931,820 8/1955 Germany.

JAMES KEE CHI, Primary Examiner. 

